The present disclosure belongs to the field of machining of chamfers of holes. The hole chamfering device includes blades in bilateral symmetry and a blade distance adjusting, through the blade distance adjusting, the distance between the blades on the left side and the right side can be adjusted, thus, after the blades on the left side and the right side of the hole chamfering device process chamfers on the front face of a hole, the distance between the blades is reduced to enable the blades to pass through the hole to process chamfers on the back face of the hole, after processing of the chamfers on the back face of the hole is completed, the distance between the blades is reduced, the hole chamfering device not only can chamfer the front face of the hole, but also can chamfer the back face of the hole.

The present disclosure belongs to the field of machining of chamfers of holes. The hole chamfering device includes blades in bilateral symmetry and a blade distance adjusting, through the blade distance adjusting, the distance between the blades on the left side and the right side can be adjusted, thus, after the blades on the left side and the right side of the hole chamfering device process chamfers on the front face of a hole, the distance between the blades is reduced to enable the blades to pass through the hole to process chamfers on the back face of the hole, after processing of the chamfers on the back face of the hole is completed, the distance between the blades is reduced, the hole chamfering device not only can chamfer the front face of the hole, but also can chamfer the back face of the hole.

A boring head includes a housing having a first end configured to be coupled to a machine tool and a second end positioned opposite from the first end with the housing defining a central passageway. The boring head also includes a diameter adjustment mechanism comprising a sliding holder received by the housing and movable relative to the housing with the sliding holder configured to be coupled to a cutting insert and a balancing mechanism having a balancing mass. The balancing mechanism is configured to move the balancing mass when the sliding holder is moved. The balancing mass is aligned with the sliding holder in a direction extending about perpendicular to a longitudinal axis of the housing.